Pseudo-melanism, also called abundism, is another variant of pigmentation, characterized by dark spots or enlarged stripes, which cover a large part of the body of the animal making it appear melanistic.[4] A deficiency in or total absence of melanin pigments is called amelanism.

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Melanism related to the process of adaptation is called adaptive. Most commonly, dark individuals become fitter to survive and reproduce in their environment as they are better camouflaged. This makes some species less conspicuous to predators, while others such as black panthers use it as a foraging advantage during night hunting.[6] Typically, adaptive melanism is heritable: A dominantgene, which is entirely or nearly entirely expressed in the phenotype is responsible for the excessive amount of melanin.

Industrial melanism is adaptive melanism caused by anthropogenic alteration of the natural environment in terms of industrial pollution. As soot, smoke and other industrial pollutants from factories darken the landscape and because many organisms rely on camouflage to avoid predation, this sudden change in their environment makes them highly vulnerable to predators. This creates a strong selective pressure which will see any organism with a darker colour much more likely to survive and contribute to the gene pool of the next generation. Rare mutations are hence selected for and over time the population will adjust to a new equilibrium.[8]Peppered moth evolution is commonly used as an example of industrial melanism.

Genetic research has shown that melanistic wolves owe their coloration to a mutation that first arose in domestic dogs

Melanin has several physiological roles in maintaining health, such as the synthesis of vitamin D. Melanin is the primary determinant of the degree of skin pigmentation and protects the body from harmful ultraviolet radiation. Synthesis of 1,25-dihydroxyvitamin D3 in the skin, however, is dependent on ultraviolet B light. Highly pigmented skin, to the level found in people of African origin, abrogates almost all ultraviolet-induced 1,25-(OH)2D3 synthesis. Numerous animal models and clinical studies have underlined the essential role of vitamin D as a modulator of the different processes of the immune system. Evidence indicates that serum concentrations of 1,25-(OH)2D3 and the prevalence of autoimmune diseases in a certain population are associated with the latitude at which that population resides.[15]

Genes for melanism in felines may provide resistance to viral infections. A viral epidemic may explain the prevalence of black leopards in Java and Malaysia, and the relatively high incidence of black leopards and black servals in the Aberdares region of Africa. Previously, black furred felines in the Aberdares had been considered a high altitude adaptation since black fur absorbs more heat.[16]

Studies reported in New Scientist magazine in 2003 also suggested that recessive-gene melanism is linked to disease resistance rather than altitude. Melanistic cats may have better resistance to disease than cats with “normal” color coats. This would explain why recessive melanism persists when melanistic individuals are disadvantaged because they are poorly camouflaged in open areas.